Gas Transport

• Oxygen dissociation curves show the affinity of haemoglobin for oxygen
• Carbon dioxide is carried in solution and bound to haemoglobin in the blood
• Carbon dioxide is transformed in red blood cells into hydrogen carbonate ions
• The Bohr shift explains the increased release of oxygen by haemoglobin in respiring tissues
• Chemoreceptors are sensitive to changes in blood pH
• The rate of ventilation is controlled by the respiratory control centre in the medulla oblongata
• During exercise the rate of ventilation changes in response to the amount of CO2 in the blood
• The pH of blood is regulated to stay within the narrow range of 7.35 to 7.45